By 2050, 14 million older persons in the United States are expected to have dementia. It is well known that persons with dementia are at increased risk of developing delirium or acute confusional state. Further, current evidence suggests that delirium may worsen the prognosis of dementia, may alter the clinical course and trajectory of cognitive decline, and may be associated with substantially worse long-term outcomes. However, the problem of delirium superimposed on dementia (DSD) remains a neglected area of clinical investigation. The proposed study is a prospective cohort study design involving 165 hospitalized subjects with dementia who are 65 and older and includes a 3-month follow-up period. Our aims for this study are: 1) to identify risk factors for DSD, and 2) to describe post-hospital outcomes and the trajectory of cognitive decline for DSD, which will justify the development of appropriate preventive and management strategies for delirium in patients with dementia. Delirium will be assessed daily from admission to discharge and then at 1 and 3 month follow-up using the Confusion Assessment Method (CAM). The potential risk factors that will be examined are divided into 3 major axes of related variables, including: 1) polypharmacy (central nervous system-active medications, number of medications, new medications added), 2) physical stressors (urinary tract infection, pain, dehydration), and 3) environmental stressors (bedrest, restraints, room changes). The primary outcomes which will be measured include: hospitalization length of stay, cognitive decline, and functional status. Outcomes will be assessed by research staff blinded to the study aims. Other baseline measurement tools will include the Folstein Mini-Mental State Examination (MMSE), Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE), Cornell Depression Scale, Delirium Rating Scale (DRS-R-98), Katz ADL Scale, Lawton Instrumental Activities of Daily Living Scale (IADL), Charlson Co-morbidity Index, Apache II, the Clinical Dementia Rating scale (CDR), a family semi-structured interview form, and a Modified Blessed Scale. Risk factors and outcomes will be analyzed utilizing multiple logistic regression, analysis of covariance, and mixed model repeated measures analyses to examine differences between those diagnosed with DSD and those with dementia only at baseline. Our long-term objectives are to use the results from this study to design and test an intervention strategy to improve early recognition, management, prevention, and outcomes in persons with DSD. This research targets a growing public health problem of preventable problems in persons with dementia. Ultimately, the results from this and subsequent studies should improve the lives of persons with dementia and their caregivers by decreasing delirium-related complications and hospitalizations. [unreadable] [unreadable] [unreadable]